FORM 2
THE PATENT ACT, 1970 (39 OF 1970)
AND
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(Section 10; rule 13)
“MAGNETIC SHIELD - STRUCTURAL MEMBER OF MOVING CONTACT
ASSEMBLY”

APPLICANT NATIONALITY ADDRESS
NOVATEUR
ELECTRICAL &
DIGITAL SYSTEMS
PRIVATE LIMITED INDIAN 61/62, Kalpataru Square, 6th Floor Off Andheri- Kurla Road, Andheri (East) Mumbai Mumbai City MH 400059 IN
THE FOLLOWING COMPLETE SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

TITLE:
MAGNETIC SHIELD – STRUCTURAL MEMBER OF MOVING CONTACT ASSEMBLY
FIELD OF THE INVENTION:
The present invention mainly discloses switching devices having an isolation capability, which possess an ability to make, break and carry current. The said device also has an ability to switch the load from one source to another source or break the power to the load through manual operation or through automatic operation. The present invention mainly discloses an assembly of comprising of a moving contact conductor, a magnetic shield and a contact pressure spring, the said assembly being easy to assemble and being effective in shielding the magnetic effects of fault conditions within the switch.
BACKGROUND OF THE INVENTION:
In general the aforementioned kind of switches are with knife/Blade type of contact systems. However, they may include other known types of philosophies as well. Contact elements for these switches include fixed contacts and moving contacts. These along with the mechanical operating means lead to switching action in the said assembly. Generally moving contacts are spring loaded in order to provide the required contact pressure while switching and continuous operation to ensure the proper flow of current within the safe thermal boundaries.
In abnormal conditions, i.e. during the fault conditions, the voltage and current in the switching device changes extremely rapidly and there is heavy interaction from the forces of electromagnetism over the mechanical systems and current carrying components themselves. During the said conditions, the mechanical structures inside the product experience a repelling as well as attracting force, thereby leading to the build-up of stress on the components supporting the current carrying conductors. e.g. if two parallel conductors carry equal current in them, they tend to attract each other. On the other side, unequal currents or equal and opposite currents repel each other. Therefore, these

electromagnetic forces need to be suppressed in order to keep the disturbances during the fault current from damaging the product. Hence, the said moving copper conductors require magnetic shielding to nullify any adverse effects and also to maintain necessary contact pressure. The assembly of moving copper conductors, magnetic shields and contact pressure springs holds together during working conditions provide the same. Further, the product architecture, space and assembly conditions are improved with the present assembly as there are lesser number of components present. In general if an assembly possesses more components, controlling the operating limits of many components during abnormal operation conditions will be difficult. The present invention solves this problem by providing a unique constructional aspect in the assembly member of the moving contact conductor, the magnetic shield itself and the contact pressure spring within a confined space limit. The assembly makes it easy to assemble and effective in shielding the magnetic effects of fault conditions.
Patent No. WO 2014/001029 discloses a three position load breaking isolating switch where fixed contacts and rotary moving contacts have sliding action and a separate arc quenching mechanism is mounted within. However the said invention mentions nothing related to magnetic shielding in rotary kind of switches.
Patent No. US20030094438A1 discloses a vacuum interrupter in coaxial manner where shielding arrangement is provided by dedicated annular disc supported to contacts and surrounding tube having thick walls. However the said invention mentions nothing related to magnetic shielding in rotary kind of switches
Patent No. US9653232B2 discloses a rotary electrical switch where actuating mechanism and contacts are within the housing. Rotary contacts and fixed contacts create a rotary bridge during switching. All rotary contacts are parallel with having common axis of rotation. Although the actuating manner is same in this invention when compared to the present invention, the contact system does not elaborate the arrangement of magnetic field and actual contact spring element assembly.
Patent No. JP5734529B2 discloses an electromagnetic operating device used as an operating mechanism for a switching device such as a circuit breaker. However, this invention discloses a switching action which is controlled by separate electromagnetic coil which enables opening and closing action.

Patent No. JP5408334B2 discloses a contact switching device suitable for a power load relay or an electromagnetic switch. A contact opening and closing device characterized in an outer peripheral portion of a metal degassing pipe fitted into the through hole via the metal annular member is brazed to the metal annular member.
Patent No. WO2001067477A1 discloses a switchgear which includes linearly-displaceable contact support, comprising a case-like housing with guide grooves, running in the direction of travel of the contact support. Conventional pivoting contacts are arranged on the contact support as displaceable switch contacts. However, in the present invention operation is done by driving a contact mechanism disposed in the sealed space based on excitation and demagnetization of the electromagnet disposed in the sealed space.
Further, none of the prior arts mention a unique constructional aspect in the assembly member of the moving contact conductor, the magnetic shield itself and the contact pressure spring within a confined space limit. Further, the assembly makes it easy to assemble and is effective in shielding the magnetic effects of fault conditions in such switches.
OBJECT OF THE INVENTION:
The object of the present invention is to provide a constructional aspect in the assembly comprising of a moving contact conductor, a magnetic shield and a contact pressure spring within a confined space and is easy to assemble.
Another object of the present invention is that the said assembly is effective in shielding the magnetic effects of fault conditions within the switch.
Brief Description of Drawings:
Fig 1: Isometric view of pole switch assembled with operating mechanism and operating handle.

Fig 2: Sectional-cut View pole switch assembled with operating mechanism and operating handle in OFF position.
Fig 3: Sectional-cut view pole switch assembled with operating mechanism and operating handle in ON position.
Fig 4: Pole switch without moving contact assembly
Fig 5(a): Pole switch with moving contact assembly in OFF condition.
Fig 5(b): Pole switch with moving contact assembly in ON condition.
Fig 6: Magnetic shield with detailed features.
Fig 7: Magnetic shield with moving contact.
Fig 8: Magnetic shield with moving contact and contact spring.
Fig 9(A): Mirrored Symmetric arrangement of Magnetic shield, moving contact and contact spring.
Fig 9(B): Vertical sectional view for Mirrored Symmetric arrangement of Magnetic shield, moving contact and contact spring.
Fig 10: Magnetic field around the conductors of moving contact system
Fig 11(A): Moving contact assembly
Fig 11(B): Horizontal sectional view of Moving contact assembly.
Fig 11(C): Vertical sectional view of Moving contact assembly.
Fig-11D: Vertical sectional view of Moving contact assembly after contact erosion.
DETAILED DESCRIPTION OF INVENTION:
The present invention will now be described with the help of the accompanying drawings wherein the same numerals are used to denote the same part. However, the drawings only illustrate the invention and in no way limit the invention.
The present invention mainly relates to switching devices with rotary or linear motion to switch the circuit ON and OFF with isolation or without isolation function. Usually these type of switches make, break or carry current with limited or infinite duty. Contact system of these devices are constructed in such a way to have single break or more breaks to

effectively disconnect the circuit with contact separation between fixed contacts and moving contacts. This type of an arrangement needs the rigid and robust moving contact assembly to ensure that the proper spring forces and magnetic shielding occur along the moving contact path, to ensure that the desired current is carried in a specified manner. As shown in Fig. 1, these type of switches are constructed in such a way that an operating mechanism (1) may be modular or inbuilt which will drive the moving contacts of individual pole (2) through a single carrier or modular carrier either in linear motion or in rotating motion, to make and break the circuit and to ensure the continuous carrying of currents. Operating mechanism (1) as shown in Fig. 1, of these switches has an operating handle (3) which is driven by the user for ON and OFF operation. In this case, usually operating handle (3) indicates the ON or OFF position of pole switch (2). As shown in fig. 2, pole switch (2) integrated with the contact system which has fixed contacts (6) and (7) and moving contacts assembly (4) which is driven in rotary motion to make and break current. Here in these switches, switching actions is provided by external mechanism (1) which incorporates toggle type of mechanism to produce the quick making and breaking conditions. During this movement, moving contact system (4) needs to go through high mechanical dynamic forces and electromagnetic forces. Fig. 2 shows the position of moving contact assembly (4) during OFF condition. Similarly Fig. 3 shows the position of moving contact assembly during ON condition. These figures mainly provide and lead to the particular design for the magnetic shield element (10) which is the part of moving contact assembly (4) to ensure the required functional and operational aspects of the switch.
The present embodiment of invention mainly discloses a modular rotary type pole switch with knife/blade type contact system. However, the said invention is not limited to the rotary type of contact systems and its utility can be expanded to other various other types of contact systems as well with equal or more effectiveness.
As shown in Fig 4, a pole switch (2) consists of case (5) and cover (not shown), a fixed contact upper side (6) and a fixed contact lower side (7) which are enclosed in a case (5) with proper fixing. The moving contact assembly (4) kept inside the case (5) as shown in Fig. 5A as conforming normally OFF condition. Fig. 5B shows the position of moving

contact assembly (4) during ON condition ensuring proper contact between fixed contacts 6 and 7. Switch will operate between OFF and ON positions as shown in fig 5A and 5B.
Fig.6 discloses the construction of magnetic shield whose features ensure the required functioning of the product. The magnetic shield (10) effectively nullifies the effect of electromagnetic force interactions with the mechanical and electrical systems of the product. The equal currents flowing in the two conductors (11) during normal operations and the magnetic attraction forces created by the magnetic shields during the abnormal operating conditions keeps the product performance at its best. This magnetic shield (10) also features an efficient support feature for the members of the moving current carrying conductor. With lesser number of components, the life of the sub-assembly is higher and thereby leads to lesser disturbances in the product lifecycle. The arrangement of the magnetic shield component (10) providing the interlocking feature in the assembly is not constrained by various other methods.
All the three parts (9)(10)(11) can be held together as shown in fig 8. By using two numbers of this part in an assembly (Fig.8) the same leads to make the moving contacts structure in a symmetric manner as shown in Fig.9A. Further, Fig.9B shows the sectional view of assembly of two numbers of copper contacts (11), two numbers of magnetic shield (10) and two numbers of contact spring (9) held together rigidly with the help of contact spring deflection action. This creates an active & counter-active working mode that enhances the product performance. The spring that is always pushing the contacts towards each other provide equal area for force balance in the normal conditions. In the abnormal conditions, when the forces are different due to higher electromagnetic & electrodynamic forces, the magnetic shield provides that additional compensations necessary for the assembly to stay stable. This assembly is guided inside the rotor shaft (8) with necessary guiding as disclosed in Fig. 11A and 11B. Pursuant to the same, the supporting pole pin (12) kept inside plastic rotor shaft (8), helps to restrict the contacts block (Fig.9A) which means that it does not come out during working conditions as shown in Fig.11B. This confirms the moving contact assembly (4).

Also, Fig.10 shows the electrical benefits for this type of contact systems. Here the same is supposed to keep the two conductors in parallel and the current flows through both the conductors (11) in the same direction. Magnetic lines of force are generated as shown in a circular pattern. This electromagnetic field generated within the magnetic shield will attract the other magnetic shields along with the current carrying conductors as shown in Fig. 10 which improves the product performance in operating conditions.
Fig. 11D shows Vertical sectional view of Moving contact assembly after the contacts (11) erosion. The position of moving contacts (11) in engagement with fixed contacts (6)(7) deteriorates. During this condition, the gap (13) between the two moving contacts tends to reduce in line with the contact erosion after repeated usage. After the erosion (Shown in dark black portion in dotted circle in Fig. 11D), there shall be reduction in contact pressure due to reduced load length of the holding leaf springs (9). However, due to the magnetic forces that develop in the magnetic shield (10), the contact pressure will improve the product performance during all times.
The magnetic shield (10) in addition to the mechanical magnetic stability it offered to the contact system, also offers a thermal advantage to the product. The magnetic shield (10) effectively acts as a thermal sink whereby it conducts heat generated at the contact system to the environment keeping the thermal conditions of the contact system at the desired levels. During abnormal conditions, the effect of heat generation will be detrimental and might lead to welding or increased erosion. During such time, the magnetic shield offers higher contact pressure and the higher contact surface area for heat dissipation through conduction and convection.
In addition to all the advantages of the above, the component necessarily splits the current passing through the moving contacts (11) into four different paths, two paths through the moving contacts (11) and two paths through magnetic shield (10) itself. This in turn reduces the net current density of the current carrying conductors keeping the contact system relatively cool compared to the other non-magnetically shielded contact systems.

In AC systems, the magnetic shield (10) reduces the skin and proximity effect due to multiple current carrying paths and constrained construction.
In DC systems, magnetic shield (10) provides a sustainable magnetic spring action due to the very nature of the currents leading to the betterment of the contact system that is required for the challenging DC parameters.
Thus the magnetic shield component that can support the contact system and the product with the mechanical, electromagnetic and thermal means forming an ideal combination of the contact system philosophy

I/We Claim:
1) A modular rotary type pole switch comprising:
a case (5), a fixed contact upper side (6) and a fixed contact lower side (7) wherein a moving contact assembly (4) is placed inside the case (5).
2) A moving contact assembly as claimed in claim 1 comprising a magnetic shield (10), a moving contact spring member (9) and a copper contact member (11), wherein 2 of such each aforementioned members are arranged together in an interlocked arrangement.
3) A magnetic shield as claimed in claim 2 which nullifies the effect of electromagnetic force interactions with the mechanical and electrical systems of the product by equalising the current flowing in the two conductors (11) during normal operations and whose magnetic attraction provides shielding effect during the abnormal operating conditions.
4) A magnetic shield as claimed in claim 3 which acts as thermal sink whereby it conducts heat generated at the contact system to the environment keeping the thermal conditions of the contact system at the desired levels and offers higher contact pressure and higher contact surface area for heat dissipation through conduction and convection during abnormal conditions.

5) A magnetic shield as claimed in claim 3 which splits the current passing through
the moving contacts into four different paths, two paths through the moving contacts and two paths through magnetic shield itself which aids in reducing the net current density of the current carrying conductors keeping the contact system at a cool temperature as compared to the other non-magnetically shielded contact systems.